CRU's new CRUTem4, hiding the decline yet again

Over at Steve Milloy writes:

Skeptic Setback? ‘New’ CRU data says world has warmed since 1998 But not in a statistically significant way.

Gerard Wynn writes at Reuters:

Britain’s Climatic Research Unit (CRU), which for years maintained that 1998 was the hottest year, has published new data showing warmer years since, further undermining a sceptic view of stalled global warming.

The findings could helpfully move the focus from whether the world is warming due to human activities – it almost certainly is – to more pressing research areas, especially about the scale and urgency of human impacts.

After adding new data, the CRU team working alongside Britain’s Met Office Hadley Centre said on Monday that the hottest two years in a 150-year data record were 2005 and 2010 – previously they had said the record was 1998.

None of these findings are statistically significant given the temperature differences between the three years were and remain far smaller than the uncertainties in temperature readings…

And Louise Gray writes in the Telegraph: Met Office: World warmed even more in last ten years than previously thought when Arctic data added

Some of the change had to do with adding Arctic stations, but much of it has to do with adjustment. Observe the decline of temperatures of the past in the new CRU dataset:


UPDATE: 3/21/2012 10AM PST – Joe D’Aleo provides updated graphs to replace the “quick first look” one used in the original post, and expands it to show comparisons with previous data sets in short and long time scales. In the first graph, by cooling the early part of the 20th century, the temperature trend is artificially increased.In the second graph, you can see the offset of CRUtemp4 being lower prior to 2005, artificially increasing the trend. I also updated my accidental conflation of HadCRUT and CRUTem abbreviations.


Data plotted by Joe D’Aleo. The new CRUTem4 is in blue, old CRUTem3 in red, note how the past is cooler (in blue, the new dataset, compared to red, the new dataset), increasing the trend. Of course, this is just “business as usual” for the Phil Jones team.

Here’s the older CRUTem data set from 2001, compared to 2008 and 2010. The past got cooler then too.


On the other side of the pond, here’s the NASA GISS 1980 data set compared with the 2010 version. More cooling of the past.


And of course there’s this famous animation where the middle 20th century got cooler as if by magic. Watch how 1934 and 1998 change places as the warmest year of the last century. This is after GISS applied adjustments to a new data set (2004) compared with the one in 1999

Hansen, before he became an advocate for protest movements and getting himself arrested said:

The U.S. has warmed during the past century, but the warming hardly exceeds year-to-year variability. Indeed, in the U.S. the warmest decade was the 1930s and the warmest year was 1934.

Source: Whither U.S. Climate?, By James Hansen, Reto Ruedy, Jay Glascoe and Makiko Sato — August 1999

In the private sector, doing what we see above would cost you your job, or at worst (if it were stock data monitored by the SEC) land you in jail for securities fraud. But hey, this is climate science. No worries.

And then there’s the cumulative adjustments to the US Historical Climatological Network (USHCN)


All up these adjustments increase the trend in the last century. We have yet to witness a new dataset release where a cooling adjustment has been applied. The likelihood that all adjustments to data need to be positive is nil. This is partly why they argue so fervently against a UHI effect and other land use effects which would require a cooling adjustment.

As for the Arctic stations, we’ve demonstrated recently how those individual stations have been adjusted as well: Another GISS miss: warming in the Arctic – the adjustments are key

The two graphs from GISS, overlaid with a hue shift to delineate the “after adjustment” graph. By cooling the past, the century scale trend of warming is increased – making it “worse than we thought” – GISS graphs annotated and combined by Anthony Watts

And here is a summary of all Arctic stations where they cooled the past:. The values are for 1940. and show how climate history was rewritten:

CRU uses the same base data as GISS, all rooted in the GHCN, from NCDC managed by Dr. Thomas Peterson, who I have come to call “patient zero” when it comes to adjustments. His revisions of USHCN and GHCN make it into every global data set.

Watching this happen again and again, it seems like we have a case of:

Those who cool the past are condemned to repeat it.

And they wonder why we don’t trust them or their data.


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It’s a travesty!


Cripes, if the past gets much colder I’ll have died in infancy.

Hey, when in trouble inflate the temperature
gives nice warm feeling.

What’s wrong with Ust Cilma in Russia, where they could not for the life of them cool the past?

Nigel S

The past is a foreign country they do things differently there.

Jimmy Haigh.



Also, I’m commenting under a new (genuine) email address because I’m told to log in via a method that I’m not sure exists.

There is of course nothing wrong with amending data in the light of increasing knowledge. But that implies a process which can be explained and justified, which is transparent and is published so that all can understand and comment.
To date I’m not aware of whether we’ve seen anything other than approaches which are obscure, unexplained, opaque and hidden.

Paul Coppin

“‘New’ CRU data says world has warmed since 1998 But not in a statistically significant way.”
When are scientists and writers going to get that these statements are oxymoronic?

Michael D Smith

The arctic adjustments just in the last few weeks by GISS have been truly amazing. It is really bold, blatant in-your-face stuff, which as far as I know has not been explained. Steve Goddard explains how the Iceland bureau of meteorology is not impressed, but it looks like is broken at the moment or I would provide the link. It looks like Envisat might be infected too, the sea level just increased 4mm a couple of days ago, on a system that showed a downtrend.
Check your spelling above… look for artic.


Do you know if the base period changed from version to version (of either HadCrut or GISS)?
I am just curious, because if the baseline changed from 1951 – 1980 to 1961 – 1990, I could see how this would “cool” the past, as the baseline period was warmer than the previous baseline.
Anyway – just curious.


From Ole Humlum, Professor of Physical Geography, University of Oslo, Norway.
The Arctic is the only place where it has been a titchie bit warmer and yet the ice grows!


Pressed “enter” in haste to try to be first tp comment. H?T to

Ted G

Data fudging has become a pay packet and a way of life for them that is addictive, an addict will at least admit he is addicted but guy’s like Hanson are incapable of telling the truth, their world is a nefarious underworld of lies ,dam lies and more lies. Their manipulations are so obvious that even amateurs like myself can see them.

A fizzyfist

When is someone going to stop this fraud

Rob Crawford

So, really, it’s not that the planet’s getting warmer, it’s just that history keeps getting colder.

I beg to differ

The answer is a question: Do you get more money from an increasing average global temperature or from a global temperature that stays the same?
In our increasingly bueaucratic world the answer is always that which benefits the bureaucracy most.


These guys are obviously frauds but what gets me is that they aren’t even particularly good frauds. So why does anyone believe their crap?


Statistically, shouldn’t adjustments themselves have zero trend? It looks like the adjustments themselves account for 0.5 deg C per century of warming.

David Jay

But if the past keeps getting colder and colder, shouldn’t we worried about the massive increases in glaciation that will result from that colder past?

Michael D Smith

So if I’m reading this correctly, 60% (0.6°/1.0°) of all of the change in temperature anomaly, aka global warming, from any cause, is due to adjustments… Got it.

Interstellar Bill

Climate science is to science as:
social justice is to actual justice
a strait jacket is to a dinner jacket
a people’s republic is to an actual republic

Jim Clarke

“Worse than we thought” is looking better all the time!
The problem the warmest are going to run into by cooling the past is that the average Joe is going to look around and realize that all this alleged warming hasn’t really caused any significant problems. Meanwhile, cap and trade, or other regulations, are hitting the average Joe pretty hard, with the promise of a lot more pain in the near future.
They may be able to tweak some emotions with their virtual temperature shenanigans, but they have little control over reality, which is consistently telling the masses that these folks are crying wolf. There just isn’t an problem with this ‘ worse than we thought’ warming. People are asking themselves, “If this warming is so bad, why aren’t we suffering at least a little bit from it now?”
Its a good question that the warmest can only answer with hand waving. The average Joe is just not as dumb as the warmest think. And since the ‘intelligentsia’ no longer have complete control over the dissemination of information, the average Joe is getting a little smarter.


data fudgers

Ian S

There are some of us ‘hard core’ skeptics that question if the Earth has warmed at all over the last century. Looking at the magnitude of the one-way ‘corrections’, can you blame us?

Michael T in Craster, UK

0.04C in 12 years – this is significant (even without error bars)? Poor LuLu…(poor DT).

Coach Springer

Obvously, using state of the art trend analysis, the solution to present day warming is to wait for the future. Today gets cooler and cooler after 25 years and then cooler yet every 7 years further into the future. “Further undermining the alarmist view of a warming world.”

So, the future isn’t becoming warmer, its the past that’s getting colder! I therefore predict a 20 deg C anomaly increase by 2100. Please forward my Nobel prize to: B Mount, c/o CRU Promotions, UK.


Interesting to find that Lerwick is in the Arctic.
And just a tiny nitpick – “Shetland”, not “Shetland Isles”.

David A

The arctic adjustments also carry more geographical weight as the GISS 1,200 K radius is not moderated by near by stations, as there are no “near by” stations. Adjust the right stations and you pretty well cover the entire arctic all the way to the pole.

David A

Of course Hadcrut and GISS will now move even further from the satelite measurements. Any minute now we can expect Steve Mosher to swing by to tell us that is all a-ok, when clearly it is not.


If at first you don’t succeed, try try again.


This is why the Arctic Sea Ice levels are so important.


CRU appears to have taken a page straight out of Peter Gleick’s strategy book. If the raw data does not fit your beliefs then manufacture the data you expected and then publish it.
MacArthur Geniuses all of ’em!

Maurizio Morabito (omnologos) says:
March 19, 2012 at 10:13 am
What’s wrong with Ust Cilma in Russia, where they could not for the life of them cool the past?
They don’t like that kind of stuff.

Where are the error bars?
Or are people claiming to be able to measure global temperature to less than 0.01C?


Another way they are hiding the decline is to distract everyone with this data to 2010 while not updating the cold Jan and Feb 2012 data.
Only the Jan SST is available.

Jim Clarke says:
March 19, 2012 at 10:40 am
“…..Its a good question that the warmest can only answer with hand waving………”
and for our UK brethren out there in the blogosphere, a Viz Profanosuarus entry would be testiculating – adverb- to wave ones arms around and talk bollocks. That’s closer to the mark for our warmista friends.

Paul Matthews

Iceland Met Office monthly temps for Reyjavik 1940:
1.6 1.7 -0.2 3.0 7.6 ….
CRUTEM4 (as used in HADCRUT4) from Met Office crutem4 download page:
1.2 1.3 -0.6 2.6 7.2 ….
So CRU are also cooling the past in Iceland like GHCN/GISS, but not so badly, ‘only’ 0.4 degrees

richard verney

I personally consider this to be counter productive to “the cause”.
With all these adjustments, one can have no confidence in the record. GISS has been adjusted perhaps a dozen times. Why have all these adjustments been necessary? Why were the past adjustments wrong? At the very least, it suggests incompetence or at any rate that the person making the adjustment does not know what they are doing. One cannot easily justify why it is necessary to have say twelev attempts to get something right. I think that the lay person readily understands that (i) it suggests incompetence, and/or (ii) it is indicative of some agenda.
Whilst I consider that there probably has been some warming this past century, I cannot with any measure of confidence conclude that it is warmer today than it was in the 1930s or the 1880s and I am fairly confident that as far as the USA is concerned, it was warmer in the USA in the 1930s than today.
The more that they adjust temperatures upwards, the more it suggests that there is no significant harm in rising temperatures. There has been no statistically significant increase in huricans, typhoons, flooding etc so what is the problem?

Bill Illis

They’ve been getting away with it since 1987 so why would they stop now.
The satellite record is the only reliable one since we can’t even be sure that the Raw NCDC climate database is still using the old records as they received them.

Werner Brozek

By Louise Gray
Now a new analysis of land and sea temperatures, that includes new data from weather stations in the Arctic, has found the world is warming even more than previously thought.
Between 1998 and 2010, temperatures rose by 0.11C, 0.04C more than previously estimated.
Professor Phil Jones, director of CRU, who was at the heart of the Climategate scandal, said the temperature series is slightly warmer because it includes the new data from the Arctic, where the world is warming faster.

With regards to the top comment, how can “the world (be) warming even more” if it has not been warming for 15 years by their own admission? For proof of the lack of warming for about 15 years, see:
As for the second statement, I think it was phrased poorly. On the HadCRUT3, 1998 was 0.07 C hotter than 2010. But apparently now 2010 is 0.04 C hotter than 1998, so the net relative change is 0.11 C. And presumably, this is mainly due to the Arctic as the third statement implies. The RSS data only go to 82.5 degrees north. I do not know about the original HadCRUT3 data, but if we assume the same, and if we assume just the northern arctic is affected since that is all we mainly hear about, that represents 1/230 of the total area of the earth. So how much warmer does this area have to be to make a net difference of 0.11 C? That would be 0.11 C x 230 = 25.3 C! See:
I do not see a huge difference between 1998 and 2010. Do you? Are we really expected to believe that in all cases where there was missing data, the 1998 values were cooler by a huge margin and 2010 was warmer by a huge margin?


Yup. Global warming is whatever HADCRU says it is on any given Monday.
First they got rid of the MWP. Now they’ve gotten rid of flatlined temperatures over the past 15 years.

Ken Harvey

Nothing wrong with that. They’ve got a time machine. They just go back and change the actual temperatures. Nothing to see here.

The only problem with the GHCN is bad story is that I dont use it and I get the same answer.
go figure.


As George Orwell wrote in his most famous novel, 1984:
“he who controls the past controls the future, and he who controls the present controls the past”.
Of course, as far as the CRU is concerned Orwell forgot to insert the words “temperature data” after “past”, “present” and “future.”

Steve C

The ‘dancing data’ animation alone demands one hell of a good explanation. Someone should make a badge of it.

Hot under the collar

Good Grief Mann,
It was that cold when I was born I must have been a polar bear!
OK I admit it, that was me in the photo on the melting ice, I was trying to get somewhere warmer, it was blooming cold mum but I didn’t know I was a polar bear…… life makes sense now…

Old England

I want to see people go to jail for this – this continuing deception and the barefaced efforts to perpetuate it deserve no less.

And, now we can all see the human influence on our temps. ……. apparently, the is the “A” in CAGW.
I fluid and dynamic history. Orwell couldn’t have written it any better.